In order to test the authors intriguing hypothesis that topical beta blockers improve acute migraine we will need a well-designed, statistically valid, large sample size, randomized, double masked, placebo controlled, clinical trial that would have defined primary outcome measures as well as strict inclusion and exclusion criteria.

Palinopsia can be broadly defined as the persistence or recurrence of an image after the stimulus has been removed. Formed, high-resolution afterimages are typically more alarming to patients than unformed, blurred afterimages.